1. Field of the Invention
The present invention relates to industrial furnaces and incinerators and, more particularly, to an inclined furnace grate structure by means of which the fuel is advanced over a succession of downwardly stepped banks of grate bars. In at least some of these banks of grate bars, alternate grate bars execute longitudinal reciprocating movements to enhance the combustion process.
2. Description of the Prior Art
Furnace grate structures of the type mentioned have been known for a long time. They are especially suitable for furnace installations which burn low-energy solid fuels and combustible solid refuse with optimal efficiency. The reciprocating action of the movable grate bars and the cascading arrangement of successive banks of grate bars on downwardly stepped transverse grate beams make it possible to obtain a very effective stoking action.
The stoking action of such a furnace grate is readily adaptable to different requirements, through separate adjust ability of the grate bar movements in the various banks of grate bars. This adaptability gives the inclined furnace grate the capability of being used in furnaces which have to burn a wide variety of solid fuels.
In operation, the grate beams and grate bars of such a furnace grate structure are subjected to elevated thermal stress. In order to withstand this stress, the grate beams are normally grey iron castings and the grate bars are harder chromium-alloyed castings.
Over a period of time, the reciprocating movements of the grate bars produce mechanical wear and abrasion on the supporting surfaces of the grate beams. This wear condition is aggravated by the fact that small solid fuel particles tend to penetrate between the sliding surfaces, where they act as an abrasive substance between the sliding surfaces.